Project Summary Pediatric anorexia nervosa (AN) affects 400,000 adolescents in the US with devastating consequences including growth delay, bone density loss, bradycardia, and the highest mortality rate of any psychiatric condition (11.5%), with half of all deaths due to suicide. Early intervention in adolescents is life-saving, making pediatric AN treatment an important public health concern. The goal of pediatric AN treatment is to restore the adolescent back to a healthy weight and reverse the dangerous effects of malnutrition. Family based therapy (FBT) is the gold standard of treatment for pediatric AN; however, 50% of patients do not respond. The consequences of treatment non-response are dire, underscoring the importance of improving treatment via augmentations to address non-response. One barrier to treatment response in pediatric AN is expressed emotion (EE), which is defined as a family's response to an ill patient that is characterized by hostility, critical comments, and emotional overinvolvement. Several studies have highlighted that families with high EE undergoing treatment for their adolescent with AN have poorer outcomes, including higher drop-out rates, lack of weight restoration, and less improvement in eating disorder symptoms. Conversely, parental warmth, a facet of EE, is associated with good outcomes in FBT. Recent parenting interventions focused on emotion coaching (EC) to address high EE have demonstrated success as adjuncts to evidence-based treatments in other pediatric populations (e.g., PTSD, ADHD) but have not been applied to pediatric AN. Given the detrimental effects that high EE has on the re-feeding process and the benefits of parental warmth, emotion coaching has the potential to reduce high EE, increase parental warmth, and improve weight restoration in adolescents with AN. The aim of this R34 pilot effectiveness trial is to conduct a two-stage study to evaluate the effectiveness of a FBT + EC parent group intervention within a clinical setting. In Stage 1 (Feasibility Stage; Year 1), we will conduct preliminary feasibility and acceptability testing of an EC parent group intervention in 6 patients with pediatric AN and their families who exhibit elevated EE. The data from the Feasibility Stage will be used to modify session content to improve treatment delivery and the uptake of EC skills. Once our manual is refined and finalized, we will conduct a randomized controlled clinical trial (Stage 2) of 50 adolescents and their parents to compare FBT+EC parent group (n=25) versus FBT+support (n=25). The FBT+support condition is a general parent support group that is offered as part of standard care in our clinical Eating Disorders Program. FBT will be identical in both the treatment and control conditions, with the EC parent group sessions and parent support group sessions occurring separately from the FBT sessions. If the aims of the project are achieved, this study would have a large impact on pediatric AN with the potential to improve weight restoration outcomes by augmenting FBT for families high in EE.